#include <termios.h>
#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
#include <string.h>
#include <jni.h>

#include <android/log.h>
static const char *TAG = "serialPortData";

#define LOGI(fmt,args...) __android_log_print(ANDROID_LOG_INFO,TAG,fmt,##args)
#define LOGD(fmt,args...) __android_log_print(ANDROID_LOG_DEBUG,TAG,fmt,##args)
#define LOGE(fmt,args...) __android_log_print(ANDROID_LOG_ERROR,TAG,fmt,##args)

static speed_t getBaudrate (jint baudrate)
{
	switch (baudrate) {
	case 0:return B0;
	case 50:return B50;
	case 75:return B75;
	case 110:return B110;
	case 134:return B134;
	case 150:return B150;
	case 200:return B200;
	case 300:return B300; 
	case 600:return B600;
	case 1200:return B1200;
	case 1800:return B1800;
	case 2400:return B2400;
	case 4800:return B4800;
	case 9600:return B9600;
	case 19200:return B19200;
	case 38400:return B38400;
	case 57600: return B57600;
	case 115200: return B115200;
	case 230400: return B230400;
	case 460800: return B460800;
	case 500000: return B500000;
	case 576000: return B576000;
	case 921600: return B921600;
	case 1000000: return B1000000;
	case 1152000: return B1152000;
	case 1500000: return B1500000;
	case 2000000: return B2000000;
	case 2500000: return B2500000;
	case 3000000: return B3000000;
	case 3500000: return B3500000;
	case 4000000: return B4000000;
	default: return -1;
	}//switch
}




JNIEXPORT jobject JNICALL Java_com_x210_android_serialPortSample_SerialPort_open(JNIEnv *env,jobject thiz,jstring path,jint baudrate)
{
	int fd;
	speed_t speed;
	jobject p_FileDescriptor;

	/*Now,check the baudrate!*/
	speed = getBaudrate(baudrate);
	if (speed == -1) {
		LOGE("Invalid baudrate");
		return NULL;
	}

	/*Next,open the device!*/
	jboolean iscopy;
	const char *path_utf = (*env)->GetStringUTFChars(env,path,&iscopy);
	/*For debug in this place*/
	LOGD("Opening serial port %s",path_utf);
	//The "O_DIRECT " has been killed,but i do not know why?

	fd = open(path_utf,O_RDWR | O_SYNC);
	LOGD("open() fd = %d",fd);
	/*Release string*/
	/*If I use const path_utf here ,the program will crash!*/
	(*env)->ReleaseStringUTFChars(env,path,path_utf);

	/*Unfortunately,OPEN FAILED!*/
	if (fd == -1) {
		LOGE("Cannot open port");
		return NULL;
	}

	/*Next,Let's configure device*/
	struct termios cfg;
	LOGD("Configuring serial port");

	if (tcgetattr(fd,&cfg)) {
		LOGE("tcgetattr() failed");
		close(fd);
		return NULL;
	}

	cfmakeraw(&cfg);
	cfsetispeed(&cfg,speed);
	cfsetospeed(&cfg,speed);

	if (tcsetattr(fd,TCSANOW,&cfg)) {
		LOGE("tcsetattr() failed");
		close(fd);
		return NULL;
	}

	/*Finally,we create a corresponding file descriptor*/
	jclass cFileDescriptor = (*env)->FindClass(env,"java/io/FileDescriptor");
	jmethodID iFileDescriptor = (*env)->GetMethodID(env,cFileDescriptor,"<init>","()V");
	jfieldID descriptorID = (*env)->GetFieldID(env,cFileDescriptor,"descriptor","I");
	p_FileDescriptor = (*env)->NewObject(env,cFileDescriptor,iFileDescriptor);
	(*env)->SetIntField(env,p_FileDescriptor,descriptorID,(jint)fd);

	return p_FileDescriptor;
}

 /*Class: ConfigSerialPort
  *Method:close
  *Signature: ()V
  **/
JNIEXPORT void JNICALL Java_com_x210_android_serialPortSample_SerialPort_close(JNIEnv *env,jobject thiz)
{
	jclass SerialPortClass = (*env)->GetObjectClass(env,this);
	jclass FileDescriptorClass = (*env)->FindClass(env,"java/io/FileDescriptor");

	jfieldID mFdID = (*env)->GetFieldID(env,SerialPortClass,"mFd","Ljava/io/FileDescriptor;");
	jfieldID descriptorID = (*env)->GetFieldID(env,FileDescriptorClass,"descriptor","I");

	jobject mFd = (*env)->GetObjectField(env,thiz,mFdID);
	jint descriptor = (*env)->GetIntField(env,mFd,descriptorID);

	LOGD("close(fd = %d)",descriptor);
	close(descriptor);
}

